Weighted Average Calculator
Compute the weighted mean of values with individual weights or frequencies.
Inputs
The data values.
Corresponding weights — must have the same count as values.
Weighted Average
86.3000
Weighted Sum
863.0000
Total Weight
10.00
Step by step
Multiply each value by its weight
85×3=255.00; 90×4=360.00; 78×2=156.00; 92×1=92.00
Sum of weighted values
85×3 + 90×4 + 78×2 + 92×1
= 863
Sum of weights
= 10
Divide weighted sum by total weight
863 ÷ 10
= 86.300000
How it works
The weighted average multiplies each value by its corresponding weight, sums those products, and divides by the total weight. Unlike a simple mean, values with higher weights contribute more to the result.
Formula
Weighted Average
Weighted Average = Σ(value × weight) / Σ(weights)
- xᵢ
- Each data value
- wᵢ
- The weight for value i
- n
- Number of values
Frequently Asked Questions
When should I use a weighted average instead of a simple average?
Use it when values have different importance, frequency, or reliability. Common examples: GPA (credits as weights), portfolio returns (investment amounts as weights), and survey data (sample sizes as weights).
What if all weights are equal?
When all weights are equal, the weighted average reduces to the simple arithmetic mean.